Fig. 1

EAE impairs olfaction during the early and chronic phases of the disease. A Study design of two different behavioral olfactory tests. Examinations were done at onset of EAE (n = 8) and during chronic EAE (n = 10) compared to the healthy group (n = 10). Visualization done with Biorender. B Preference to sniff the new odor vanilla during trial 2 of the odor discrimination test in healthy mice (n = 10), during onset of EAE (d9 p.i., n = 8) and chronic EAE (d25 p.i., n = 10). Unpaired, two-tailed Student's t-test was performed for statistical analysis. C Preference to sniff the new odor almond during trial 3 in percentage in comparison to a control odor exposed to healthy mice (n = 10) as well as at the onset of EAE (d9 p.i., n = 8) and during chronic EAE (d25 p.i., n = 10). Unpaired, two-tailed Student's t-test was performed for statistical analysis. D–F Total time sniffing D and self-grooming E and number of rearing events F in the first trial of the odor discrimination test in healthy mice (n = 10), EAE mice at disease onset (d9 p.i., n = 8) and during the chronic EAE phase (d25 p.i., n = 10). Unpaired, two-tailed Student's t-test was performed for statistical analysis. G, H Percentage of time the mice were immobile after exposure to 2,5-dihydro-2,4,5-trimethylthiazoline (TMT), measured in 2 min bins, in healthy mice (n = 10) and at the onset of EAE (n = 10) G, as well as in healthy mice (n = 9) and in mice during the chronic phase of EAE (n = 10) H. Graphs show the posthoc test after performance of REML mixed-effects model with Šídák multiple comparison. *P < 0.05, **P < 0.01, ***P < 0.001